Numerical control system

ABSTRACT

In the numerical control mode of the present invention, an incremental command and an absolute command are used together within a single block, thereby simplification of the programming process and extreme preciseness in the numerical control system being achieved.

WP m 1 825, 31. 451 July" 23,1974.

NUMERICAL CONTROL SYSTEM 966 Gotz et al United States- Patent Kobayaslliet al. I

Motooka et al 'Reuteler McGee Jerua et al.

' Slawson Me b wu ah w mn .ana

Kmw

Re n 8% n w [73] Assignee: Fujitsu Limited, Kawasaki-sin,

Japan c 22 Filed: Jan. 5, 1973 Primary Examiner--Fclix'D. Gruber 2 Appll321 3 3 Assistant Examiner-Jerry Smith Attorney, Agent, or Firm-RobertE, Burns; Emman- Related Apphcatlon Data 1 uel J. Lobato; Bruce L. Adams[63] Continuation-in-part of Scr. No. 104,086, Jan. 5,

l97l, abandoned.

[30] Foreign/application Prior ty Data ABSTR Jan. 30, 1 970 45-7958, 52us. 235/151.11, 318/569, 318/570 f h vnurrmical cdntrol' m h present i[51' Int. G06f 15/46 lion, an incremental c m and an absolute vvcom- [58], Field of Search 235/1-511'1;318/569, 570, n r usediwgether Within'aSingle block, y

' I v 313/573 00 01 simplification of 'the programming process andextreme preciseness in the numerical control system- [56] ReferencesCited being achieved;

UNITED STATES PATENTS I v 13,246,125 4/1966 Mer gler 235/151 .11 X 3Claims, 30 Drawing Figures CSTPR-- 2.3 EMCZDOQ mmmmooq N w w w w P H Wx4 T R m5 T U U C U Gm ,N l. l E C x m m mmkw R R R P mac aw wm 21 5 DY. W, W a 51 l R M 02 M w R 95 P mfg t ,zmm T, G G m WNW .I 9P9 m mg m w"R w 96 wmu S C .tw R 3P0 R mm 8mm 9102 5 C E l1 E C D W T m mn C R 91 mo NMPWP ammo. mR W in M2 Bw Fun m MQAQ W M W N; 6 8 .m Pw .i 5 0mm 1 o0:, 5 N Q05 T wow 3 w wow v0 J l m v Ba no lwmwm (mm 1 5 W R m Noam .N R9 Q05 c Qm mm 1 A mow E No.1 R

ARITHMETIC OPERATION CIRCUIT (RGT) PATENTEB 3.825.731

sum 02 or 18 SB PB SF NUMERAL BIT F /B SIGN B SPACE BIT LINEAR COMMANDPAR'TY ABSOLUTE COMMAND BSOLUTE cOMMAND AIR GOl -o z'o o-'--o CR);ABsOLUTE COMMAND F/g. lC

INCREMENTAL. COMMAND [CR GOI UOO---c wo o---o CR] ;|NcREMENTAL COMMANDF/g /D ABSOLUTE COMMAND INCREMENTAL COMMAND INCREMENTAL SOLUT OMM N[COMMAND- ABIEC AD /CR (50! 2'0 o--O w'oO--- OCR UOO O--O z'O O---o CR/;U5E A550 LUTE CO- L 1 BLOCK l BLOCK MAW? l H INCREMEN- q- /E COMMANDCOUNTERCLOCKWISE DIRECTED CIRCULAR INTERFORATION ABSOLUTE COMMANDINCREMENTAL COMMAND L X0 o---o oo---O io 0 0 koo---o R? ;USE ABSOLU- L ATE MAND v 1' BL C INCREMENTAL COMMAND PATENIEUJULNISM 3.825.731

sum "osnr 18 Fig. 5

SNW IAXDZOGBPNI S mamm 3.825.731

l (NI) moan mam} PATENIEfl-M 3.825.731

saw 050F18 Fig. /OA

CLOCK PULSE I I] 1| I I H H H H n F/g/OB W 2-PHASE RING COUNTER (g mflAl 1 I 1 yr? Fig. lOC

3- PHASE RING COUNTER (SEN/AR COUNT T l j msmznmw 3.025.131

sum '11 or 1a Fig. /3

" READ IN CIRCUIT (RRD) READ IRDFI CONTROL l JO] CIRCUIT 'RDFZ @5 J J02J03 INPUT J04 CIRCUIT J05 (IN) jg? PATENTEUJULZBW 3.825.131

SHEET 12 11f 18 Fig. /5

J10 J11 J16 J17 PRE- PROCESSING COUNTER (PRC) INPUT CIRCUIT? DEN XAR J12Z AR 5 tnxAR tnzAR J15 PAIENIW 3.825.731

sum 150MB I LIN CIR

DISTRIBUTION CIRCUIT (PDC) PATENTEDJULZSIHH 3.925.131

sum -1s 'nr 18 Fig. /8

PATENTED 2 31974 sum -11 or )a Fig, /9-0 bution.

. the present invention;

. NUMERICAL CONTROL SYSTEM DESCRIPTION OF THE INVENTION Thepresentapplication is a continuationdn-part of the application Ser. No.l04,086,filed Jan. 1971, and now abandoned. j g

The present invention relates to a numerical control system wherein bothan increment system and absolute system are employed in combination.

There are two principles'in the technique of indicating the amount ofmovement in the numerical control system, one being the increment systemwherein the amount of movement is instructed in reference to the actualposition of toolwithin given ordinates and another being the absolutesystem wherein the position ordinates are instructed within ordinatesbased'on a prescribedlygiven fixed point as the origin point of theordinates. Both systems being accompanied by respective merits anddemerits, suitable selection has been exerted on both systems inaccordance with need in the actual utilization in the conventionalnumerical control systems. I g

An object ofthe present invention residesin the provision of a numericalcontrol system wherein both a.

word based on the absolute system and a wordbased on the incrementalsystem can be used together so that programming may be easilyaccomplished.

The present invention is characterized in that, in a numerical controlapparatus wherein the numerical control system is provided with aregister for storing the values of the-actual tool coordinates, aregister for storing the command values and-an arithmetic operationcircuit for carrying outan arithmetic operation with the assistance bythe abovementioned registers, the increment cornmandsare distinguishedfrom the absolute FIGS 6 7A and 7Bfare graphs explaining pulse 'dis--tribution along an arc;

FIG. '8 is a flow chartexplaining pulse distribution .alongan arc;

FIG. 9 is a block diagram illustrating the relationship between thepre-processing airthmetic operation function and the other operationfunction;

FIGS. 10Athru 101) are waveform diagrams explaining the operationof theaddress'counter AT of F IG. 9;

FIG. 11 is a preferred embodiment of the internal circuit diagram of theaddress counter AT of FIG. 9;

FIG. 12 is a preferred embodiment of the read control circuit RRC ofFIG. 9; FIG. 13 is a preferred embodiment of the read in circuit RRD ofFIG. 9;

FIG. 14 is a preferredembodiment of the prethe distribution circuitPDCof .FIG. 9;

commands'by symbols such as alphabets prefixing the quirethe'incrementalvalue for performing-pulsedistri- The'present inventionwill be made more apparent from the ensuring description, referencebeing made to the accompanying drawings, wherein: 1

FIG. I is a block diagram of the arithmetic operation circuits of thenumerical control system according to FIG. 1A is a schematic viewillustrating the construction of a register employed circuit of FIG. I;9

FIGS. 18 through 1B are partial schematic views of various program tapesused in the numerical control system according to the present invention,in which metic operation function of the numerical control systemaccording to the present invention;

FIGS. 3 and 4 are graphs explaining pulse d'stribution along a straightline; I

FIG. 5 isa flow chart explaining pulse distribution along a straightline; M I i in the arithmetic operation FIG. 17 is a preferredembodiment of the distribution command circuit PDD of FIG. 9;

' FIG. 18 is a preferred embodiment of the gate circuit RGD of FIG. 9;

' FIG. 19 is a table illustrating correlation between inputs andoutputsof the gate circuit RGD of FIG. 9.

Referring to FIG. 1, R to R are registers having 24 bits, respectively;as shown in FIG. 1A.'Registers R,

and R store the absolute actual positions of tools of afabricating-machine, the registers R and R store the sated and thediscriminating equation for the pulse distribution and, the register Rstores the Z-component of the values ofthe new tool to be compensated.RF is a velocity register. GT01 to GT09 designate the gate signals ofthe above-mentioned respective registers.

When the signals GT21 to GT24 become l the content of'the bus Cis'written into the register selected by the gate signals GTOl to GT0 8.GT10 is a signal to be impressed to theil circuit. When thesignalGTlO'is .l, the i1 circuit adds I to the content of the bus B soas to transmit it to the bus C whereas, when the signal GT10 is 0, itadds +1 to the content of the bus B so as to transmit it to the bus C.

The signals GTlS and GT17 are switching signals of the complementalcircuit C/T and, when that signal is 1, the complementof the inputnumerical value is produced at the output side of the complementalcircuit C/T. FA is a full adder, 1D is l-bit delay circuit, 090 is aplus-minus distinguishing circuit, SMEl 'to SME3 are flip-flop circuits,PIC is a parity bit insertion circuit connected-to the bus C, PAC andPBC are parpreceding the relevant numerical values. For example,

it is supposed that X and Z are absolute commands, u., w, i, k, areincremental commands,- t and t are compensated values of the old tooland t and r designate

1. A numerical control system for controlling the movement of a tool ofa machine tool comprising: a. an input circuit receptive of signalshaving information content representative of discrete positions to whicha tool of a machine tool is to be moved, said signals being grouped insequential blocks wherein information content of said signals comprisingeach of said blocks represents a plurality of command numerical valuesrepresentative of said positions to which said tool is to be movedreferred to an equal number of reference axes and corresponding toindications if said command numerical values correspond to incrementalcommands or absolute commands and includes command direction informationindicating directions in which said tool is to be moved, said inputcircuit developing output signals having the information content of thereceived signals; b. means for generating timing pulses; c. apre-processing counter for developing a predetermined sequence of outputsignals in response to said timing pulses applied thereto and inresponse to a signal applied thereto indicating a block of said receivedsignals were received by said input circuit; d. means for applying saidtiming pulses to said pre-processing counter; e. means for generatingand applying to said pre-processing counter said signal indicating ablock of said received signals were received by said input circuit; f. agate circuit for developing gate signals in response to read commandsignals and operation command signals applied thereto; g. read circuitmeans receptive of said input circuit output signals for developing andapplying said read command signals applied to said gate circuit; h.pre-processing command circuit means receptive of said preprocessingcounter output signals for developing in response thereto said operationcommand signals and for applying said operation command signals to saidgate circuit; i. an arithmetic operation circuit comprising a pluralityof registers for storing position information of said tool referred tosaid reference axes and said command numerical values, said arithmeticoperation circuit comprising means for simultaneously converting saidcommand numerical values which are absolute commands into equivalentincremental commands and replacing said absolute commands stored in saidregisters with said equivalent incremental commands, and computingposition information of a subsequent position of said tool from saidposition information stored in said registers and from said incrementalcommands and replacing said position information with said subsequentposition information in response to said gate signals; j. means forapplying said input circuit output signals and said gate signals to saidarithmetic operation circuit; k. pulse distribution circuit means fordeveloping and applying pulse distribution control signals to said gatecircuit in response to said timing pulses and one of said pre-processingcounter output signals applied thereto, said gate circuit developing andapplying gate signals to said arithmetic operation circuit in responseto said pulse distribution control signals, said arithmetic operationcircuit applying said incremental commands to means for positioning saidtool in response to said last-mentioned gate signals, said pulsedistribution circuit means comprising means for developing and applyinga signal to clear and reset said pre-processing counter after saidincremental commands are applied to said means for positioning saidtool; and l. means for applying said timing pulses and one of saidpreprocessing counter output signals to said pulse distribution circuit.2. A numerical control system for controlling the movement of a tool ofa machine tool according to claim 1 wherein said pre-processing countercomprises a plurality of flip-flops in cascade.
 3. A numerical controlsystem for controlling the movement of a tool of a machine toolaccording to claim 1 wherein said input circuit comprises means forreceiving said received signals and said received signals havinginformation content indicating if said command numerical valuescorrespond to incremental commands or absolute commands correspond toselected alphabetic letters.